Hand grenades are small explosive, incendiary, or smoke producing devices thrown by military or law enforcement personnel in the course of military or law enforcement operations. Hand grenades typically have a body that contains an explosive or chemical filler and a fuze that ignites or detonates the filler in the grenade. The fuze contains a powder train that provides a time delay between the arming of the grenade and the actual detonation of the grenade. The fuze is lit by the action of a spring loaded striker mechanism impacting a primer which ignites a delay element that burns for a predetermined time and then detonates the filler. Typically, the grenade is prevented from being armed by a safety handle that blocks the striker mechanism from impacting the primer. A safety pin locks the safety handle to prevent the arming of the grenade. When the safety pin is withdrawn, the safety lever is free to release from the body of the grenade. When the safety lever is released, the striker spring unwinds and the striker rotates on axis to impact the primer, which then creates a flash of heat that ignites one end of the delay element. The delay element burns down to an igniter at the other end of delay element, which then sets off the main charge or filler of the grenade.
There exists a hazard, regarding grenades of this configuration, wherein, if a user relaxes his grip on the safety handle, after the safety pin has been removed, the striker may rotate and impact the primer, causing the fuze to light unbeknownst to the user. The lit fuze causes a chain reaction leading to detonation of the grenade. This may occur even though the safety handle has not been fully released, and also despite the user, perhaps, returning the safety handle to the initial, fully compressed, position. This is referred to as ‘milking’ a hand grenade, and has been the cause of numerous serious injuries and fatalities. Even though the problem has existed for decades, there have, heretofore been no solution to allow for detection of a milked grenade.
What makes this circumstance particularly dangerous is, where if a user may recompress their grip and the safety lever returns to the initial fully compressed position, there is a false sense of security that the grenade fuze is not initiated. Existing designs exacerbate the situation because there is no means of determining either visually, tactilely, or audibly, that a grenade has been ‘milked’ as any indication of such is hidden under the safety lever. The quandary in such a situation is that the safety lever would have to be lifted to determine if the grenade had been milked, but lifting of the safety lever would ensure the activation of the grenade. Further, a user who ‘milks’ a grenade may likely do so in such a subtle or transient manner, or under such stressful or expedient circumstances, that it would not occur to the user that any milking may have occurred. Thus, there would not be cause to determine if ‘milking’ had occurred, even if a means for detection should exist. If a user had a quick and safe indication that ‘milking’ occurred, and the fuze had been initiated, he would likely have time to dispose of the grenade. This would prevent many serious injuries and fatalities. Further, it would be highly advantageous for such and indicator to be manifestly self-evident, and discernable to a user without the need for close, purposeful, inspection.
Prior art grenades address the issue of unintentional activation of a grenade via inadvertent removal of hand pressure offer solutions directed at decreasing the likelihood of the grenade being activated via said inadvertent hand pressure release, rather than providing any indication that such an activation has taken place: U.S. Pat. No. 2,203,640 issued to Hines, U.S. Pat. No. 4,926,752 to DiRubbio et al., and U.S. Pat. No. 5,196,649 also to DiRubbio et al. A grenade arming state indicator of U.S. Pat. No. 8,561,540 issued to Lauch involves providing a visual indication of the state of an arming thumb switch, which is essentially an additional safety, and does not provide any indication of whether the striker assembly has been activated nor does it provide an indication of whether the grenade has been initiated.
Thus a need exists in the art for a safety indicator mechanism to allow the grenade user to quickly and reliably discern striker activation and grenade initiation, without the need for purposeful inspection of the grenade by the user.